The Laverda Field; Evidence for Stratigraphic Compartmentalisation in A Deepwater Setting
Woodside Energy Ltd.
The Laverda Field was discovered in offshore Western Australia in October 2000 with the drilling of Laverda-1 which encountered a 72 metre oil and gas column in the Late Jurassic to Early Cretaceous Macedon Sandstone. Laverda-2 was drilled in 2002, 3.4 kilometres to the north-northeast of Laverda-1 and found a separate 34 metre gas column. Further extension of the field to the north was tested in 2003 by the Skiddaw-1 and Skiddaw-2 wells which both found thin unconnected hydrocarbons. At the end of this campaign Laverda was considered to be very complicated with multiple hydrocarbon pools with different geochemistry and sands of varying ages.
In 2010 a new depositional model was proposed based on the con-sistent integration of all data and by placing the field in its regional geological setting. Laverda-1 is now interpreted to sit within a seismically mappable canyon that has cut down into the "older" more sheet-like sands of Laverda-2, Skiddaw-1 and Skiddaw-2. The canyon's western edge appears to form the sealing boundary between the Laverda-1 and Laverda-2 hydrocarbon pools.
The model was successfully tested in 2011 with appraisal of the canyon via the Laverda North wells which encountered similar stratigraphy and pressure to Laverda-1 well. The area down dip and to the west of Laverda-2 in the "older" sands was also appraised with the well encountering a gas column in apparent communication with Laverda-2 and an oil leg. The final appraisal well Laverda East-1, encountered water wet "older" sands outside the canyon to the east and up dip of the Laverda North wells with only the canyon’s eastern edge separating the wells.
AAPG Search and Discovery Article #90200 © AAPG Geoscience Technology Workshop, Fifth Annual AAPG-SPE Deepwater Reservoir, January 28-29, 2014, Houston, Texas